1. Field of the Invention
The present invention relates to an optical lens system, and more particularly to a miniaturized optical lens system for taking image used in a camera mobile phone.
2. Description of the Prior Art
In recent years, with the popularity of camera mobile phone, the optical lens system for taking image has been becoming thinner and thinner, and the sensor of a general digital camera is none other than CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). Due to advances in semiconductor manufacturing, the pixel size of sensor has been being reduced continuously, and miniaturized optical lens systems for taking image have increasingly higher resolution. Therefore, the demand for the image quality becomes increasingly urgent.
A conventional mobile phone's lens assembly usually consists of three lens elements: from the object side to the image side: a first lens element with positive refractive power, a second lens element with negative refractive power and a third lens element with positive refractive power, thus forming the so-called type of Triplet. To correct the aberration, the optical lens system usually takes the form of “front aperture stop”. However, the arrangement of front aperture stop will increase the occurrence of stray light and the sensitivity of the optical lens system.
The present invention mitigates and/or eliminates the afore-described disadvantages.